Oxidation reactions are one of the most basic reactions in the organic chemical industry, for which various oxidation methods have been developed. Patent Literature (PTL) 1 describes a method for oxidizing a compound capable of forming a radical typically with molecular oxygen under catalysis of a lipid-soluble imide compound. Disadvantageously, however, the method fails to use a commercially available imide compound as intact as a catalyst, the method uses the lipid-soluble imide compound that is hardly prepared by synthesis, and the method suffers from a very low yield when normal alkanes (linear alkanes) are used as the substrate even when the lipid-soluble imide compound that is hardly prepared by synthesis is used.